A long time ago.....
.....a chap of my acquaintance who did the escape and evasion course was questioned by an interrogator who he assumed was either a CS or an Auxiliary. After the questions which he said were the ones they'd been briefed on and could have come from his service records they suddenly changed tack and were deeply personal stuff not likely to be in records.
He said he then lost the plot and began to believe it was no longer an exercise.
Finally it stopped and he was told the ex was over but he then refused to believe them and stuck with the number rank name bit. It was a day and a half before he "came down". Eventually they brought in the interrogator, who had been one of his school teachers which was where all the really personal stuff had come from. He never really forgave them.
The Ancient Mariner